Both matter, though one can never tell listening to some of you sub 20 posters. I wouldn't have experienced great subs if I never ventured down this road. However, it doesn't mean that a few words of caution is a bad thing. I am not sure why it makes some of us feel good about ourselves to make-believe that we are envied. This is a forum so there should be multiple perspectives.

As a poster who has been labeled by your sort for nearly a decade as "a frequency response Nazi", "on a quest for 3 Hz Nirvana", "obsessed with single digits" and every other really cool descriptive label you could ever imagine, I'll take your post to include me. Sub 20 poster is another good one for the scrap book.

When a question is asked, it should be answered using the facts. Opinions that are contrary to the facts should be part of a new thread started by the person whose philosophy is 'opinions are more important than the facts'. At the very least, the hyper-20 posters should qualify with IMO.

Above 20 Hz is stupid easy. SVS and Hsu have been doing it since the 90s on-the-cheap. There are a billion threads that extol the virtues of such a sub, most of which were steered by the employees of those companies.

Those threads contain a billion posts that allege <20 Hz is inaudible, so irrelevant, unintended artifact, mistakenly left on the disc through careless production, too expensive to reproduce, only in soundtracks of movies that suck, on too few discs to care about, invites alien abduction and whatever other opinions (or, words of caution?) on that side of the fence.

But after all of that, "a word of caution' is still required and necessary in a thread that asks "why <20 Hz matters"?

One is free to use the search function and read until he's blind if he prefers to know why <20 Hz does NOT matter, but, with all due respect, it doesn't belong in this thread.

As a poster who has been labeled by your sort for nearly a decade as "a frequency response Nazi", "on a quest for 3 Hz Nirvana", "obsessed with single digits" and every other really cool descriptive label you could ever imagine, I'll take your post to include me. Sub 20 poster is another good one for the scrap book.

When a question is asked, it should be answered using the facts. Opinions that are contrary to the facts should be part of a new thread started by the person whose philosophy is 'opinions are more important than the facts'. At the very least, the hyper-20 posters should qualify with IMO.

Above 20 Hz is stupid easy. SVS and Hsu have been doing it since the 90s on-the-cheap. There are a billion threads that extol the virtues of such a sub, most of which were steered by the employees of those companies.

Those threads contain a billion posts that allege <20 Hz is inaudible, so irrelevant, unintended artifact, mistakenly left on the disc through careless production, too expensive to reproduce, only in soundtracks of movies that suck, on too few discs to care about, invites alien abduction and whatever other opinions (or, words of caution?) on that side of the fence.

But after all of that, "a word of caution' is still required and necessary in a thread that asks "why <20 Hz matters"?

One is free to use the search function and read until he's blind if he prefers to know why <20 Hz does NOT matter, but, with all due respect, it doesn't belong in this thread.

Bosso

A hint or articulation and reason may have been the intent. Instead, we are presented with a paradox. The title of the thread and the very first post betrays you, not me. Serendipity.

A hint or articulation and reason may have been the intent. Instead, we are presented with a paradox. The title of the thread and the very first post betrays you, not me. Serendipity.

The title is asking about the measured response and why do some measurements show flat lines below 20Hz. He then asks does it matter that those measuremnts go below 20Hz. Nothing in his post talks about content and the importance of it mattering to people. He continous to wonder if it clips amps and the answer is nope.

Its interesting that you think it reads..."why does < 20Hz matter at all?" because that was not the OPs question as posted. Your point is the first time though that I even can see how some people can be misinterpeted....interesting stuff.

Hey Penn, I watched The Matrix on television last night as well on a 42 inch plasma and it's speakers. I agree with you 100% in that we do this because we enjoy it and the movie experience. I watch these movies all the time whether at reference in the theater or on my other displays. These bass scenes are great to show people(most of our friends do not know the capability of a home system) what a movie can truly sound like. It is FUN!!!!!!

I see people are saying it is only 1% or whatever, I remember the day when THX was on some laserdiscs and when DTS came out on some laser discs and then DVD and the vast majority said but who cares, it is only on some dvd's. Look where we are now. There are more and more movies coming out the utilize the full bandwidth and it is just plain fun to experience it. Should we sacrifice 20-120hz for it? No, but we can have both. The one thing I will extend on what Bosso said is that 20hz and above is no easier than 20hz and below, it just takes more money. Get a couple good sealed subs and you have 20hz and above and get acouple more with a LT circuit and you can have both. How many depends on the room and listening preference.

The Fact of the matter is that there is content going on way below 20hz and the reason for this is that they exist in real life. Why not get as real as possible(at movie levels of course, not 200dbs with real rockets). The content is there, it is up to you to decide whether you want it or not.

The title is asking about the measured response and why do some measurements show flat lines below 20Hz. He then asks does it matter that those measuremnts go below 20Hz. Nothing in his post talks about content and the importance of it mattering to people. He continous to wonder if it clips amps and the answer is nope.

Exactly. And, if you answer the question in total or in any part, you're a below 20 poster.

This Q should be a no-brainer after 20 years of discrete multi-channel audio and thousands of titles, but it's still muddied by personal preferences and biases.

The title is asking about the measured response and why do some measurements show flat lines below 20Hz. He then asks does it matter that those measuremnts go below 20Hz. Nothing in his post talks about content and the importance of it mattering to people. He continous to wonder if it clips amps and the answer is nope.

Its interesting that you think it reads..."why does < 20Hz matter at all?" because that was not the OPs question as posted. Your point is the first time though that I even can see how some people can be misinterpeted....interesting stuff.

I've seen some subwoofers mentioned to have flat response down to 16Hz (+-3dB).

Doesn't Dolby digital only support between 20Hz to 20,000Hz, not to mention most subwoofers & amplifiers only function in this range!?!

Does going down this "deep" just get clipped by most source amplifiers anyway?"

"Cool I'll check your system out

I'm running an Onkyo TX-SR608. All of the specs only indicate 20Hz-20,000Hz driven per channel.

So I assume that anything below 20Hz is just being cut off, but I'm not sure.

Right now running a single PSW505 Polk 12 in a 17x14ft room.

First going to try dual PSW505s, then sell them if need be, and get a true subwoofer that can go down to the 20's range and shake the room nicely!"

He didn't even mention a desire to go sub 20hz. Perhaps we all need a lil' dose of balance and relevance instead of defaulting to extremes. Did I mention that folks like yourself is the reason that I now enjoy good bass? I do appreciate that.

I do hope those making a choice have atleast had a proper reference point before they make a conclusion because they might not know what they are missing.

I know, that was, essentially, my point.

Admittedly, I do agree that without experiencing it it is tough to say whether it matters or not. I would imagine that is what the OP was trying to get at in the first place with his question.

Before my sealed DIY's I was quite happy with the PB13. To be frank, in my smallish room, it was giving me excellent response down low with room gain in 15hz tune. The dual AV15H's do extend lower, and for the rare occasions when that happens, it definitely puts a smile on my face. I recently had a chance to go listen to another members system which employed dual, large, ported subwoofers, and he had some decent room gain as well from 15hz to 25hz.

We listened to some bass tracks I have on a DVD (short clips from various movies like Pulse, WOTW, FOTP, etc ... you know, the mindless flicks stuff... which btw outside of WOTW I don't own the DVDs, just the short clips ). While the system performed very well, it was very evident that the experience was substantially "different" from my own room. At least to me.

To me there appeared to be more "SPL" whereas in my room there was much more "feel" and "pressure", and in some cases bass just seemed to be lacking. E.g., when the plane rolls over in FOTP, in the member's room there was a lot of SPL and it was very loud to my ears, the difference is in my room my head feels like it is going to implode. If you've been in a prop plane and experienced a shift in the atmospheric pressure or you hit an air pocket and the plane suddenly drops, you know the feeling of pressure I'm talking about. Very similar to that (maybe this is the "underwater feeling" some have noted a few times above??).

Now, his room is 2 to 3 times larger than mine of course and IMO he selected subs that fit within his budget (and was not interested in DIY), had I been in his shoes I likely would have done the same and possibly picked very similar subs. But personally I would miss the "sub 10/15/20" content after having experienced it. Even though 95% or whatever of the content of movies are not below 20hz or 30hz FTM.

On the way back the other member that came along helped drop off my old PB13 and I had him listen to the same FOTP scene (and a couple others) at my place, and he may have just been playing lip service to be nice, but he seemed to immediately understand what I was talking about on the drive back about what I felt was missing and was seemingly very impressed with the system I had.

YMMV, but it is difficult to know whether "sub (insert arbitrary number here) hz matters" without experiencing it in the first place.

If you have experienced it and don't care for it, then you've made your own bias/opinion known, and when choosing system compromises you can cross off lower than "X" hz from your requirements and focus on other aspects. If you've experienced it and care for it, then you'll have to figure out a way to make it happen within your own budget/room/box size constraints, and potentially compromise elsewhere if your budget (or room aesthetics or other ...) calls for it.

If you haven't experienced it and don't care to, again, that's fine. But don't push that it doesn't matter.

The title is asking about the measured response and why do some measurements show flat lines below 20Hz. He then asks does it matter that those measuremnts go below 20Hz. Nothing in his post talks about content and the importance of it mattering to people. He continous to wonder if it clips amps and the answer is nope.

Its interesting that you think it reads..."why does < 20Hz matter at all?" because that was not the OPs question as posted. Your point is the first time though that I even can see how some people can be misinterpeted....interesting stuff.

Quote:

Originally Posted by pbc

I know, that was, essentially, my point.

Admittedly, I do agree that without experiencing it it is tough to say whether it matters or not. I would imagine that is what the OP was trying to get at in the first place with his question.

Before my sealed DIY's I was quite happy with the PB13. To be frank, in my smallish room, it was giving me excellent response down low with room gain in 15hz tune. The dual AV15H's do extend lower, and for the rare occasions when that happens, it definitely puts a smile on my face. I recently had a chance to go listen to another members system which employed dual, large, ported subwoofers, and he had some decent room gain as well from 15hz to 25hz.

We listened to some bass tracks I have on a DVD (short clips from various movies like Pulse, WOTW, FOTP, etc ... you know, the mindless flicks stuff... which btw outside of WOTW I don't own the DVDs, just the short clips ). While the system performed very well, it was very evident that the experience was substantially "different" from my own room. At least to me.

To me there appeared to be more "SPL" whereas in my room there was much more "feel" and "pressure", and in some cases bass just seemed to be lacking. E.g., when the plane rolls over in FOTP, in the member's room there was a lot of SPL and it was very loud to my ears, the difference is in my room my head feels like it is going to implode. If you've been in a prop plane and experienced a shift in the atmospheric pressure or you hit an air pocket and the plane suddenly drops, you know the feeling of pressure I'm talking about. Very similar to that (maybe this is the "underwater feeling" some have noted a few times above??).

Now, his room is 2 to 3 times larger than mine of course and IMO he selected subs that fit within his budget (and was not interested in DIY), had I been in his shoes I likely would have done the same and possibly picked very similar subs. But personally I would miss the "sub 10/15/20" content after having experienced it. Even though 95% or whatever of the content of movies are not below 20hz or 30hz FTM.

On the way back the other member that came along helped drop off my old PB13 and I had him listen to the same FOTP scene (and a couple others) at my place, and he may have just been playing lip service to be nice, but he seemed to immediately understand what I was talking about on the drive back about what I felt was missing and was seemingly very impressed with the system I had.

YMMV, but it is difficult to know whether "sub (insert arbitrary number here) hz matters" without experiencing it in the first place.

If you have experienced it and don't care for it, then you've made your own bias/opinion known, and when choosing system compromises you can cross off lower than "X" hz from your requirements and focus on other aspects. If you've experienced it and care for it, then you'll have to figure out a way to make it happen within your own budget/room/box size constraints, and potentially compromise elsewhere if your budget (or room aesthetics or other ...) calls for it.

If you haven't experienced it and don't care to, again, that's fine. But don't push that it doesn't matter.

Well said. At what frequency range(#hz to #hz) can one experience pressurization assuming that a system is capable(relatively speaking)?

JPC is basically arguing (unless I misunderstand and we're in the same camp), that ULF isn't important, period.

PMEE start from the premise that the goal in system design is high fidelity to the source material. They argue that lots of movies have ULF, intentionally or otherwise, so we should try to reproduce it.

DS is basically arguing (and I don't misunderstand, for what should be fairly obvious reasons!) that PMEE are mostly right if one assumes that the goal in system design is high fidelity to the source material, and does not discuss system designed for other purposes one way or another due to lack of experience with and lack of interest in systems designed for other purposes.
But there is, first, a threshold question: does program material the system owner enjoys actually contain this content intentionally? While conceding that recent releases may (I'll address that more, infra), this question has been asked but simply not answered. It has simply been assumed to be the general case, when in fact it is not at all general question. It is an individualized question. Everyone's answer will be different, based on the program material that individual enjoys and thus expects to reproduce in high fidelity.
Still, let's assume arguendo the threshold question has been affirmatively answered. Then comes the balancing question. That is to say, what weight to accord ULF? IF a choice must be made - and often, due to various reasons, it must - is it worth sacrificing fidelity of other parts of the spectrum to achieve ULF? Say, using an I-B array of very high inductance subs with small mains placed so as to maximize diffraction? If one's goal is high fidelity to the source material, the answer is an obvious "no." If one has a design goal other than high fidelity to the source material, the answer may be "yes" depending on the individual's goal. (As an aside, if someone posts a picture to use as an example to support one's own POV, use of that picture by others to support their POV contrary to the author's is fair game as well.)

Penn's position is basically just postmodernism as applied to ULF. I'd write more, but apparently that's infraction-worthy.

Quote:

Originally Posted by bossobass

Check out that sloppy guy, Randy Thom. Dude has no clue what the spectra is of any of the effects he designs.

I have no idea who he is. An argument from authority is unpersuasive.

You also did not list the ULF content of all those movies.

And you may note that I have repeatedly conceded that current home movie releases have ULF content. I even mentioned the most likely reason for that: to get a sales bump by appearing in "best bass" lists. (Can we all at least accept that profit-minded cynicism, not any higher calling to art, is what dominates Hollywood?) My argument is simply to ask what the relevance of ULF reproduction is for people uninterested in special effects plotless wonders.

But that brings us to the question, "what is high fidelity to a movie?" Given that the actual event is synthesized anyway, wouldn't "high fidelity" be "recreating the event the directors intended one to experience?" That is to say, the experience of viewing a movie in a cinema. Given that even the biggest IMAXes (to my knowledge) use vented subwoofers that cannot go as low at the SPL many of our home systems can, the answer to "do even special effects plotless wonders need ULF reproduction" depends on one's answer to the fidelity question.

Quote:

Originally Posted by bossobass

Here's a recent film: HTTYD

That's an awful name for a film. I haven't even heard of it. Or is it an abbreviation for the actual name?

Quote:

Originally Posted by penngray

Im not sure how any of that matters when answering the OPs question. He asked why does < 20Hz matter and the simple fact is that there is content below 20hz even content below 10Hz. "Content" is defined simply as content, it does not matter if someone thinks its crap content or not, its simply content.

So, your position is that it's irrelevant whether a system will actually see such content, so long as it exists somewhere?

IOW, if someone listens to music basically constantly but uses the screen in his home theater to watch nothing but weekly Fareed Zakaria GPS podcasts and occasionally Daily Show over his AppleTV (honestly, a very close approximation of my TV watching in the NFL offseason), then a system designed without ULF in mind is inadequately spec'ed?

Quote:

Originally Posted by ReneV

For the people that do do ULF: how about the *flat* part of the question in the subject line?

I don't know where you'd put me, but yes, flat if the goal is high fidelity. The content creator can decide what actual level to put the content, relative to 0dBFS.

--
"In many cases there aren’t two sides unless one side is 'reality' and the other is 'nonsense.'" - Phil PlaitSerious Audio Blog

Well said. At what frequency range(#hz to #hz) can one experience pressurization assuming that a system is capable(relatively speaking)?

I've only heard bass like this once... i think it was around ~15Hz at my friends place. Might of been lower not sure... but I can't say for sure, my SVS PB10-NSD only reaches down to around 19-20Hz. I do get some response to 15Hz but the SPL isn't high enough to get that same pressure I've felt at my friends place.

Another question for all the 'below 20hz haters' (something other than movie content with sub 20hz material) if response didn't matter below that then why is there pipe organ music with sub 20hz content? Also why would there be products like the Thigpen Rotary Woofer and other products that extend down into the teens and single digits if it didn't matter. It obviously matters to some people, maybe not to you, but it obviously does matter!

The reason is just as simple as "Why are there cars that can go faster than 75mph or that can accelerate from 0-60mph in 3-4 seconds!? There is no need for a car that fast." Because some people want it! You may not use it all the time, but is sure is a hell of a lot of fun when you do!

The fact remains that there is sub 20hz material and it is there for a reason.

But personally I would miss the "sub 10/15/20" content after having experienced it. Even though 95% or whatever of the content of movies are not below 20hz or 30hz FTM.

I think that 95% number could be closer to 98% but that obviously depends what your DVD library consists of. For music, my number is 99.92% with no content < 25Hz and that's out of 10,000 tracks in my Itunes library.

You and others would miss it but subwoofer design is full of compromises and if you prioritize bandwidth (on the low end), you give up anywhere from 6 to 8dB+ of max SPL capability at frequencies > 20Hz.

Are people willing to give up let's say 6dB between 20 and 30Hz for more output at 10Hz? Remember, if you added a second identical sub to your existing single sub setup in the same position, it would add 6dB to the max SPL.

Some people buy an almost fridge sized sub so they can hear major SPL at 10Hz. Would it be desirable to half the cabinet size by volume while still matching the SPL at 20Hz but losing output at 10Hz?

Finally, a sub targeted to product max output at 10Hz is more expensive that one with a lower limit of 20Hz. Would you pay let's say 50% more for that 10Hz sub?

If you still prefer the 10Hz compromises, you really enjoy your 10Hz content or you just want to win the 'mine is bigger/better than yours" contest amongst you and your friends.

I've only heard bass like this once... i think it was around ~15Hz at my friends place. Might of been lower not sure... but I can't say for sure, my SVS PB10-NSD only reaches down to around 19-20Hz. I do get some response to 15Hz but the SPL isn't high enough to get that same pressure I've felt at my friends place.

I did get pressurization watching the flip scene in the first Transformers. However, that was on my mom's system if a very small room with a 10" infinity sub. I agree it would be cool to experience that feeling on sub 20 material to compare. Is it just more intense or different? I hope we didn't chase the OP away.

This thread is similar to "Best sub for $500" threads. Hey get the Sumbersive! No get the PB13. Naw the Captivator is IT. May I suggest the JL Gotham! Why must knowledge be a burden.

Another question for all the 'below 20hz haters' (something other than movie content with sub 20hz material) if response didn't matter below that then why is there pipe organ music with sub 20hz content? Also why would there be products like the Thigpen Rotary Woofer and other products that extend down into the teens and single digits if it didn't matter. It obviously matters to some people, maybe not to you, but it obviously does matter!

The reason is just as simple as "Why are there cars that can go faster than 75mph or that can accelerate from 0-60mph in 3-4 seconds!? There is no need for a car that fast." Because some people want it! You may not use it all the time, but is sure is a hell of a lot of fun when you do!

The fact remains that there is sub 20hz material and it is there for a reason.

There is no "class" warfare here above 20 hater, maybe one of relevance. We are just exploring the head/tail/ribbed edge of the coin. This is how I learned about the very little that I know yet still come here. There is so much more that we could be doing with our time. Yet we are here on AVS discussing bass, dynamics, relevant range, etc. It's cool really!

I think that 95% number could be closer to 98% but that obviously depends what your DVD library consists of. For music, my number is 99.92% with no content < 25Hz and that's out of 10,000 tracks in my Itunes library.

I originally put 99%, but backed down to 95%, as I have no idea what the actual number is and I didn't think 95 to 99% was that large of a difference to skew the point either way.

Quote:

Originally Posted by Sahak94

You and others would miss it but subwoofer design is full of compromises and if you prioritize bandwidth (on the low end), you give up anywhere from 6 to 8dB+ of max SPL capability at frequencies > 20Hz.

Depends on the system design to some extent. I actually chose a specific set of woofers that perform exceedingly well above 80hz and lose 2 to 3 db below say 20hz versus some others I was looking at (e.g., the CSS SDX15) specifically because I knew I had ample room gain to make up for it and amp power to EQ, and didn't want woofers that couldn't reproduce north of 80hz as I planned on crossing them at 150hz or more with my bookshelves. If I feel I'm lacking somewhere, I can always add more of the same sub.

Quote:

Originally Posted by Sahak94

Are people willing to give up let's say 6dB between 20 and 30Hz for more output at 10Hz? Remember, if you added a second identical sub to your existing single sub setup in the same position, it would add 6dB to the max SPL.

I'm sure some are. Several ID brands made a living off of this for years, and now it seems the trend is moving back to "north of 20hz" subwoofers. Likely much more profitable to make I would think, and overal cheaper so more will sell (as you allude to above). Sounds like a pretty good business decision to me.

Quote:

Originally Posted by Sahak94

Some people buy an almost fridge sized sub so they can hear major SPL at 10Hz. Would it be desirable to half the cabinet size by volume while still matching the SPL at 20Hz but losing output at 10Hz?

Depends. Look at MK, he hides his monster subs behind a screen, so it doesn't matter if they are the size of a fridge or not. Personally, I had to make sure they were aesthetically pleasing. I guess it therefore is dependent upon the persons needs/desires. Kind of like whether they feel sub 20hz matters.

Quote:

Originally Posted by Sahak94

Finally, a sub targeted to product max output at 10Hz is more expensive that one with a lower limit of 20Hz. Would you pay let's say 50% more for that 10Hz sub?

Personally, yes. Obviously as I mentioned above, may manufacturers are going the other way now to sell more at a lower cost of entry for the average consumer. But we're not talking about how much it costs to obtain sub 20hz output, nor the size of box FTM.

Quote:

Originally Posted by Sahak94

If you still prefer the 10Hz compromises, you really enjoy your 10Hz content or you just want to win the 'mine is bigger/better than yours" contest amongst you and your friends

Not sure what you're getting at here? Seems like the sentence is missing something. But in my case I wanted to get as much performance across as much of the FR range as possible without sacrificing "aesthetics" because the system is in a room where we spend 90% of our time outside of the kitchen or bedroom. For the record, none of my friends have anything remotely near what I have, and to be frank, outside of my brother and one friend (both of whom I suggested purchasing SVS subs vs some B&M brand for more money), I could have a Sony HTIB and have "as good" or better sound, nor do I go to their homes and proclaim "hey my system is way bigger/better than yours". I really could care less, because most of my time I'm watching/listening to my own system.

I think that 95% number could be closer to 98% but that obviously depends what your DVD library consists of. For music, my number is 99.92% with no content < 25Hz and that's out of 10,000 tracks in my Itunes library.

You and others would miss it but subwoofer design is full of compromises and if you prioritize bandwidth (on the low end), you give up anywhere from 6 to 8dB+ of max SPL capability at frequencies > 20Hz.

Are people willing to give up let's say 6dB between 20 and 30Hz for more output at 10Hz? Remember, if you added a second identical sub to your existing single sub setup in the same position, it would add 6dB to the max SPL.

Some people buy an almost fridge sized sub so they can hear major SPL at 10Hz. Would it be desirable to half the cabinet size by volume while still matching the SPL at 20Hz but losing output at 10Hz?

Finally, a sub targeted to product max output at 10Hz is more expensive that one with a lower limit of 20Hz. Would you pay let's say 50% more for that 10Hz sub?

If you still prefer the 10Hz compromises, you really enjoy your 10Hz content or you just want to win the 'mine is bigger/better than yours" contest amongst you and your friends.

You don't lose any output since you design a system that can handle whatever your response to be at whatever your listening goals. For movies, if that goal is reference levels and you want the full content then you build a system that can handle reference level peaks for any movie at any frequency. I mean if the system can play clean at 120 db's from say 5 hz to 120hz who cares if a 20hz and above system can play at 126 db's since 120 db's will be the max at any given time? We are not talking a single sub here, but sub systems at these levels and frequencies.

JPC is basically arguing (unless I misunderstand and we're in the same camp), that ULF isn't important, period.

Wrong. Where did I say that? Got a link?

Quote:

Originally Posted by DS-21

But that brings us to the question, "what is high fidelity to a movie?" Given that the actual event is synthesized anyway, wouldn't "high fidelity" be "recreating the event the directors intended one to experience?" That is to say, the experience of viewing a movie in a cinema. Given that even the biggest IMAXes (to my knowledge) use vented subwoofers that cannot go as low at the SPL many of our home systems can, the answer to "do even special effects plotless wonders need ULF reproduction" depends on one's answer to the fidelity question.

That is more to the point.

Just because a sound effect is encoded on a DVD with infra spectra at level X does not mean that "the premise that the goal in system design is high fidelity to the source material. They argue that lots of movies have ULF, intentionally or otherwise, so we should try to reproduce it."

Unless the program originators have full system capabilities that are flat to near DC on each and every channel, then how can anyone know what the intended effect is supposed to "sound like" (AKA infra is not audible at normal listening levels)?

Bass managed systems with all small speaker 80 Hz crossover settings do not sound the same as acoustic mixed systems. They also do not sound the same as bass managed systems that use other speaker configurations. Easy to duplicate that basic effect with a spectrogram, but no one really cares about that issue.

Anyhow, I come down on the POV that content on the main channels was intended to be rolled off by the speaker system rather than by the creator of the content. I am not sure where the low end roll off should start and what rate the rolloff should be, but I doubt that the sound design was made to be played back as designed only on systems that play flat to DC at the listening position. My system configuration does not HP filter the R & L mains so I get a natural 2nd order rolloff down to DC.

Also note that the PMEE group does not have a consistent low end design in mind. Penn noted a 10 Hz requirement, but that leaves 2 octaves of information below that point. Bosso is more a falt to DC type of PMEE. If you look at what others do rather than what they say, there are various cut off point that are based on what they own or made.

Why do theaters like IMAXs pushing Danley's shoot for ULF output when 30Hz is "plenty" for most other theaters? In fact the previous IMAX standard (still is?) was -3dB at 40Hz. What's the point of putting that much horsepower to fill an enormous room if all that ULF is unnecessary and extraneous? What does Danley know that we don't?

In addition, four new Danley TH-50 subwoofers generate the low-end rumble for avalanches and the like. Hedden summarized, “The TH-50 actually challenged the sample rate of the FFT analyzer being used in the final testing in that due to the combination of cabinets and room gain we are flat to 10Hz!"

Anyhow, I come down on the POV that content on the main channels was intended to be rolled off by the speaker system rather than by the creator of the content. I am not sure where the low end roll off should start and what rate the rolloff should be, but I doubt that the sound design was made to be played back as designed only on systems that play flat to DC at the listening position. My system configuration does not HP filter the R & L mains so I get a natural 2nd order rolloff down to DC.

I'll be putting this to the test very soon when my uber mains project is done.

Another question for all the 'below 20hz haters' (something other than movie content with sub 20hz material) if response didn't matter below that then why is there pipe organ music with sub 20hz content?

Why do you think my posts, when they have mentioned a number, used 16Hz and not 20Hz?

Quote:

Originally Posted by sickboy013

Also why would there be products like the Thigpen Rotary Woofer and other products that extend down into the teens and single digits if it didn't matter.

By that standard, why are there $3000 RCA interconnects, if do their job in a system no better (or worse, usually) than $10 RCA interconnects?

My point with the wire analogy is that the existence of a product is not proof of a useful purpose for that product.

Quote:

Originally Posted by sickboy013

The fact remains that there is sub 20hz material and it is there for a reason.

Actually, that "fact" is what is very much in dispute. Especially the second part, at least wrt everything but recently released special effects plotless wonders.

Quote:

Originally Posted by bossobass

Get with the 21st century, George... especially if you plan to direct a discussion about the relevance of <20 Hz audio.

A) My name's not George.

B) What does a movie sound-man have to do with serious audio? If you had listed a credit for producing an album (or a concert video) for the Royal Concertgebouw or Radiohead or R.E.M. or R. Kelly I might have given the reference more weight. (Specific artist names chosen for alliteration as much as anything else.) But movies? Blah. Don't care.

C) You still haven't answered my question about the one piece of musical program material you've mentioned with high ULF content. What's the musical relevance of the ULF content in that Sting song? Is it just outside noise that somebody inadvertently left in, or does it correspond to actual music?

D) You still haven't said what the title of the film you abbreviated is. How is one who doesn't particularly follow Hollywood supposed to know what you're talking about, even to the point of looking it up on a review site?

Quote:

Originally Posted by BiGBADDABOOM

Why do theaters like IMAXs pushing Danley's shoot for ULF output when 30Hz is "plenty" for most other theaters?

Because it's free. (Though I queston the ability of a TH50 or any other box that unloads below its cutout to pressurize a room below its cutoff. That cutoff may be lower for four of the boxes than for one.) Those subs have headroom benefits compared to others higher up in the spectrum, because they are more complicated boxes (6th order bandpasses with some resonant behavior overlaid atop). They make a classic tradeoff of bandwidth for efficiency.

"Because it's free" is IMO a perfectly valid reason. Enhanced ULF capability can be a happy byproduct of smart design choices that primarily benefit more musically important parts of the spectra at home as well, such as employing multiple closed-box subwoofers primarily to smooth out the upper bass response.

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"In many cases there aren’t two sides unless one side is 'reality' and the other is 'nonsense.'" - Phil PlaitSerious Audio Blog

In addition, four new Danley TH-50 subwoofers generate the low-end rumble for avalanches and the like. Hedden summarized, The TH-50 actually challenged the sample rate of the FFT analyzer being used in the final testing in that due to the combination of cabinets and room gain we are flat to 10Hz!"

Maybe he knows whether that spec applies to the content on all channels or only for the LFE channel!

Just as an additional note, the IMAX soundtrack to Apollo 13 does not sound the same as the soundtrack on the theatrical release.

I think that 95% number could be closer to 98% but that obviously depends what your DVD library consists of. For music, my number is 99.92% with no content < 25Hz and that's out of 10,000 tracks in my Itunes library.

How did you screen your library? Is there an automated program that you can run, preferably one that runs on OSX and is compatible with Apple Lossless files?

I'd like to do the same, because I'm genuinely curious. With the one exception of the Sting song Bosso posted in this thread, there is no meaningful-to-me data on the prevalence of ULF in program material. (Prevalence, of course ≠ relevance, but is the threshold inquiry.)
That is to say, I only know of one track with sub-16Hz content thus far, out of 80 days worth of CD's and digitized LP's* in my music library.
I assume there are more, but I'd like to know.

*LP's digitized with a rumble filter in the phono preamp, so unlikely to be ULF there. At any rate, the ULF content discussed here would cause a record needle to jump out of the groove anyway.

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"In many cases there aren’t two sides unless one side is 'reality' and the other is 'nonsense.'" - Phil PlaitSerious Audio Blog